Short, 18, no self confidence?

I am currently an 18 year old high schooler, I'm 5'4 and 115 pounds, I have a baby face, no real facial hair, long brown mop hair, and have never hooked up with anyone because I look so young. People often mistake me as 12 or 13 years old and I am constantly asked how old I am. I just want to look normal and all I get is too short, too skinny, and too young. Someone please help me gain confidence as I have little to none because of my appearance and don't tell me "you will be glad you look young when your older".